The Penguin Declines

Transcription

Penguins have long captured the imagination and the hearts of people the world over. But while popular culture depicts them as clumsy, adorable birds with endlessly abundant populations, the truth is that penguins are exceedingly graceful, often ornery, and their populations are in rapid free fall. Their real life situation is far more precarious than people think. And if current trends do not change, it may not be long before penguins can only be found in movies. There are many things about penguins that make them odd birds, so to speak. For one thing, they are one of the few bird species that cannot fly, having evolved from flight-capable birds about 60 million years ago. Surprisingly, their closest living relative is the albatross, a bird known for its enormous wingspan and extraordinary soaring abilities. It may seem strange that losing the ability to fly would be an evolutionary advantage, but the penguin's short, flipper-like wings and solid bones allow them to swim faster and dive deeper than any other bird on Earth, filling an ecological niche that no other bird can. Penguins inhabit the southern hemisphere, being one of the few bird species able to breed in the coldest environments. But contrary to popular belief, they are not restricted to cold regions nor are there any at the North Pole. In fact, only 4 of the 18 penguin species regularly live and breed in Antarctica. Most penguins live in subtemperate to temperate regions. And the Galapagos penguin even lives and breeds right near the equator off the coast of South America. They are also found in South Africa, Namibia, Australia, and New Zealand, as well as on a number of islands in the southern Atlantic, Pacific, Indian, and Antarctic Oceans. Although penguins spend 75% of their lives at sea, they must come to shore every year to reproduce and to molt their feathers. They do this in a variety of places, from the temporary ice sheets of the Antarctic to the beaches of South Africa and Namibia, to the rocky shores of subantarctic islands, to the craggy lava surfaces in the Galapagos. Different penguin species have different nesting practices. Some dig burrows into dirt, sand, or dried guano; some nest in tussock grasses; some build nests out of small rocks, sticks, and bones; while others don't build any nests at all. Although most penguins lay a clutch of two eggs, the two largest species, the King and the Emperor, lay a single egg that they incubate on top of their feet for approximately two months. Unfortunately, 15 of the 18 penguin species are currently listed as threatened, near-threatened, or endangered by the International Union for Conservation of Nature. In the last several decades, we have seen the world populations of most penguin species decline by up to 90%, with two of them, the Yellow-eyed and Galapagos penguins, down to just a few thousand birds. Penguins are an indicator species, the proverbial "canary in the coal mine." Simply put, if penguins are dying, it means our oceans are dying. And sadly, most of this decline is attributable to human activities. Historically, penguins have had to deal with multiple disturbances. The mass collection of penguin eggs and the harvesting of the seabird guano they nested in caused the dramatic decline of several penguin species. If you're wondering what humans would want with seabird poop, it was used as an ingredient in fertilizer and in gunpowder, being so valuable that in the 19th century, it was known as white gold. Current threats to penguins include the destruction of both marine and terrestrial habitats, introduced predators, entrapment in fishing nets, and pollution from plastics and chemicals. There have also been several large-scale oil spills over the past 50 years that have killed or impacted tens of thousands of penguins around the world. But the two major threats to penguins today are global warming and overfishing. Global warming impacts penguins in multiple ways, from interrupting the production of krill due to decreased sea ice formation in the Antarctic, to increasing the frequency and severity of storms that destroy nests, to shifting the cold water currents carrying the penguins' prey too far away from penguin breeding and foraging grounds. Even though humans may be the greatest threat to penguins, we are also their greatest hope. Many research and conservation projects are underway to protect penguin habitats and restore vulnerable populations. With a little help from us and some changes in the practices that impact our planet and oceans, there is hope that our tuxedo-clad friends will still be around in the next century.